Internal-combustion engine



July 15 1924.

F. LAGUESSE INTERNAL COMBUSTION ENGINE Filed April 1, 1922 2 fiheets-Sheet l [wi e "for L MM Jul 15 1924. 1,501,855

F. LAGUESSE INTERNAL COMBUSTION ENGINE Filed April 4, i922 2 Sheets-Sheet 2 I L'ay'u'efse Patented July is, ielze.

- FEB/HAND LAG'UESSE, 0E HERSTAL, BELGIUM.

INTERNAL-COMBUSTION ENGINE.

hpplicatiog filed April 4, 1922. Serial No. 549,555.

To all whom it may concern Be it known that I, FERNAND Lneonssn, a subject of the King of Belgium, and'resident of Herstal, Belgium, have invented certain new and useful Improvements in and Relating to Internal-Combustion Engines;

and I do hereby declare the following to.

be a full, clear, invention, such in the art to and exact description of the as will enable others skilled which it appertains to make and use the same, reference being had to theaccompanyin drawings, and to letters or figures of reference marked therein, which form a part of this specification.

This invention relates to the distribution in two stroke, internal combustion engines, having preliminary compression of the fuel mixture in the casing, and in which the cylinder admission and exhaust ports are situated at the same level, while a casing admission port for the fuel mixture is provided at another point.

A special object of the invention is to increase, as much as possible, the duration of admission into the casing and into the cylinder, while retaining the necessary advance of ton.

To effect this, according to the invention, the controlof the admission ports to the cylinder and the casing, is by means of the piston, and a single slide valve. The valve as two ports corresponding to the above said ports and is actuated by a crank oii'set 90 with respect to the motor crank. Accordingly, during descent of the piston, admission to the cylinder may still be closed by the slide valve for a time, and then opened by the valve, the admission port to the easing being closed by the slide valve during this descent of the piston, while during the ascent of the piston, the latter alone controls the distribution of the admission ports of the casing and the cylinder.

The accompanying drawings illustrate by way of example one mode of carrying the mvention' into effect.

In the drawings, Fig, 1 is a longitudinal v sectional elevation showing the engine at the beginning of the mission stroke.

Fig. 2 is a longitudinal sectional elevation of the en no at the moment when the exhaust an admission ports are closed and when the port of admission into the casing is open.

exhaust and of the adexhaust during descent of the pis Fig. 3 shows in sectional elevation the engine at the beginning of expansion period.

Figs. 4, 5 and 6' illustrate diagrammatically the position of the cranks operating the valve gear and the driving piston, corresponding respectively to each of the positions illustrated in Figs. 1, 2 and 3.

Fig. 7 illustrates on a larger scale, a horizontal section of the exhaust orifice of the cylinder of the en ine.

I Fig. 8 is a vertical section along the line A-B of Fig. 7.

in a cylinder 2 according to a two-stroke cycle and connected by means of a connecting rod 3 to a crank shaft 4 mounted in a. casing 5.

The crank shaft has one end provided with a crank 6 operating by means of a connecting rod 7 a slide valve 8 provided with two ports 9 and 10.

The said valve in combination with the piston of the engine, controls the passage of the gases into the pipes 11 of admission to the sprayer and of the pipe 12 of admission to the casing. I

Accordin to the mode of construction illustrated in the drawings, the admission ports 13, the exhaust ports 14 and the cylinder 1 are situated at the same level. Therefore, at the end of the expansion period in the cylinder, as shown in Fig. 1, the piston of the engine uncovers the ports 13 and 14. simultaneously in such a manner that in order to maintain the early exhaust which is necessary, the valve has also to close the admission pipe 11 during a certain time.

The crank 6 operating the valve having already passed at that moment considerably beyond the dead point, the speed of displacement of the valve gear producing the opening of the admission pipe 11 will be maximum for'the said opening.

The engine comprises a piston 1 moving portion of fresh gas through the exhaust port is rendered possible;

At the same time, towards the middle of the ascending stroke of the piston, the lat ter uncovers the admission port 15 due to a recess 16 provided. in the lower part of the iston.

e crank 6 of the valve gear 7 is then at about its lower dead point, in such a manner'that the-admission pipe 12 is not closed by the valve gear andthat the piston alone controls the very rapid opening of the admission port 15.

The admission may then take place until gm pgiston is in the position illustrated in The admission pipe 12 connecting the carburettor to the casin is then completely closed by the valve 8 w ile the piston commences its descending stroke in such a man: ner that'there is no: compression into the carburettor.

The fresh gases introduced into the cylinder at the end of the expansion stroke through the admission pipe 11 are directed by the deflector of the piston towards the head of the cylinder along the inner wall of the latter as shown in Fig.1.

They are thus brought in an extension 17 arranged on the head of the cylinder and intended-owingto the suitable shape of the inner wall-to' produce a current of the fresh gas in a closed circuit;

The sai moves apart until a line isreached separating the said wall from an incline 19 descending towards the opposite side oi the en trance wall for the fresh gas.-

It should be pointed out that during the ascending stroke of the piston illustrated in dotted lines in Fig. 2, the gas which is compressed between th face 20 0f the piston deflector and of the cylinder,

the portion 19 ct the head. is caused to pass through the channel formed by a portion a of t e face 20 parallellyto the axis of the-cylinder and a portion b of the deflector 19 of the cylinder head. In this narrow passage the air has a high speedand produces numerous eddies in the gas-which is compressed inside the head of the engine. Thisstirrmg of the mixture is very advantageous for a good ignition and for a complete combustion of the mixture.

inner wall hasa curvature which neonate On the other hand, with the object of avoiding the formation of too great a vacuum inside the cylinder 2 when the burnt gasleaves through the exhaust ports 14, use is made of a conical extension 21 acting as an injector intended to bring air from the outside into'the exhaust plpe.

' The said conical extension 21- commences in the neighbourhood of the exhaust pipes 14 and opens into a chamber22 formed by the exhaustpipes 23, and which is placed in communication with the outside air, on the one hand by means of conduits 24' provided in a suitable manner in the borders of the exhaust orifice, and on the other hand. by means of a conduit 25 provided inthe partition 26 arranged across the exhaust port 14. I p

The burntv gas leaving through the conical extension 21 forms a vacuum in the chamber 22 which vacuum produces'a strong in" flnx of fresh air through the conduits 24 and 25. I

This influx of fresh air helps more especially to prevent a vacuum from being produced in the compression chamber of the cylinder and at the same time to cool the borders of the exhaust orifice 14.

What I claim is:

A two cycle engine comprising inlet and exhaust ports positioned at the same level,

a conduit connectin the cylinder inlet port and the engine cra casing, a crank casing inlet port, a piston and a single slide valve,

said slide valve being provided with two ports corresponding to the cylinder and casing inlet ports, said last two ports being controlled by the piston and slide valve; a crank offset from the engine crank by approximately 90 for operating the valve, whereby, on the descent of the piston, the cylinder inlet port is first closed by the valve for a time, then opened by the valve, the casing inlet sort bein closed by the valve during the escent o the piston, and

on the upstroke of the piston, the piston controls the cylinder and the casing inlet ports.

In testimony whereof I afiix my signature in presence of two witnesses.

' FERNAND LAGUESSE. Witnesses:

Siivnm HANBENNY, Grammars MEBCKALL. 

